Recipe Measurement Converter

A recipe measurement converter changes a cooking quantity from one unit into another, such as cups into milliliters, ounces into grams, or Fahrenheit into Celsius. It is used to adapt recipes between the US, metric, and imperial systems.

What units does it convert

The converter works with three separate groups of units. It converts within a group, not between groups.

• Volume: teaspoons, tablespoons, fluid ounces, cups, pints, quarts, gallons, milliliters, liters
• Weight: milligrams, grams, kilograms, ounces, pounds
• Temperature: Celsius, Fahrenheit, Kelvin

A volume unit can be converted to another volume unit, and a weight unit to another weight unit, but volume cannot be converted directly to weight. That distinction matters for baking and is explained below.

How to calculate a volume or weight conversion

Volume and weight conversions both use the same two-step method. Every unit in a group has a fixed factor that converts it to one shared base unit. For volume the base unit is the milliliter. For weight the base unit is the gram.

Formula:

$\text{result} = \text{value} \times \text{(from-unit factor)} \div \text{(to-unit factor)}$

The value is multiplied by its unit's factor to get the base amount, then divided by the target unit's factor.

Volume factors (1 unit in milliliters)

Weight factors (1 unit in grams)

These factors also give the everyday kitchen ratios: 1 tablespoon equals 3 teaspoons, 1 cup equals 16 tablespoons, 1 cup equals 8 fluid ounces, 1 pint equals 2 cups, 1 quart equals 2 pints, 1 gallon equals 4 quarts, and 1 pound equals 16 ounces.

Temperature conversion formulas

Temperature does not use a shared multiplying factor, because the Celsius, Fahrenheit, and Kelvin scales start at different zero points. Instead, each value is converted through Celsius using these formulas.

$°C = (°F - 32) \times \frac{5}{9}$

$°F = (°C \times \frac{9}{5}) + 32$

$K = °C + 273.15$

$°C = K - 273.15$

Worked examples

Volume: Convert 1.5 cups of milk to milliliters. 1.5 × 236.588 = 354.882 mL.

Weight: Convert 8 ounces of butter to grams. 8 × 28.3495 = 226.796 g.

Temperature: Convert an oven temperature of 350°F to Celsius. (350 − 32) × 5 ÷ 9 = 176.67°C.

Why volume and weight are not interchangeable

A cup of flour and a cup of honey do not weigh the same amount, because they have different densities. Converting volume to weight, or weight to volume, requires knowing the density of the specific ingredient, not just a fixed unit factor. This converter does not perform that kind of conversion, because it has no ingredient database to draw density from. A recipe that lists "1 cup flour" can only be turned into grams accurately if the flour's density is known, which is why professional bakers often weigh ingredients directly instead of converting from a volume measurement.

Negative values and limits

Volume and weight cannot be negative, since a recipe cannot call for less than zero grams of sugar. Temperature is different. Celsius and Fahrenheit can go below zero, matching real situations such as a freezer set to -18°C. Kelvin cannot go below zero, because 0 K is absolute zero, the coldest temperature that is physically possible.

History of cooking measurement systems

Cooking recipes were not always precise. Early cookbooks described amounts as "a handful" or "a pinch." Fannie Farmer's Boston Cooking-School Cook Book, first published in 1896, told cooks that a cupful is measured level, leveled off with a knife, and so are spoonfuls. The metric system was conceived in France in 1790 and later became the standard in most of the world. The United States kept the older US customary units. This is why a US cup (236.588 mL) differs from the 250 mL metric cup used in Canada and some other countries.

Frequently asked questions

How many milliliters are in a cup? A US cup holds 236.588 milliliters.

How many tablespoons are in a cup? There are 16 tablespoons in 1 cup, and 3 teaspoons in 1 tablespoon.

Does this converter turn cups of flour into grams? No. Cups measure volume and grams measure weight, and the two are only related through an ingredient's density, which is different for every ingredient. This converter only changes units within the same category.

How do I convert an oven temperature from Fahrenheit to Celsius? Subtract 32, then multiply by 5, then divide by 9. For example, 350°F becomes 176.67°C.

Is a US cup the same as a metric cup? No. A US cup is 236.588 mL, while a metric cup, used in Canada and some other countries, is 250 mL. The difference is about 6%.

Can temperature values be negative in this converter? Celsius and Fahrenheit values can be negative, since recipes sometimes reference freezer or chilling temperatures below zero. Kelvin values cannot be negative, because 0 K is the lowest temperature possible.

References

1. National Institute of Standards and Technology. NIST Guide to the SI (Special Publication 811), Appendix B.8. Factors for units listed alphabetically — US cup 236.5882 mL, tablespoon 14.78676 mL, teaspoon 4.928922 mL, fluid ounce 29.57353 mL, pint 473.1765 mL, quart 946.3529 mL, gallon 3.785412 L, ounce 28.34952 g and pound 453.5924 g.
2. National Institute of Standards and Technology. NIST Guide to the SI (Special Publication 811), Appendix B.9. Factors for units listed by kind of quantity — the Fahrenheit, Celsius and kelvin conversion formulas.
3. Fannie Merritt Farmer, via Project Gutenberg. The Boston Cooking-School Cook Book (copyright 1896, revised edition). The Boston Cooking-School Cook Book — a cupful, tablespoonful and teaspoonful are measured level, leveled with a knife.
4. National Institute of Standards and Technology. A Turning Point for Humanity: Redefining the World's Measurement System. A Turning Point for Humanity — the original French metric system was conceived in 1790.
5. Health Canada. Measure ingredients like a pro. Measure ingredients like a pro — kitchen conversion table with 1 cup as 250 mL.